void block_store_link(block_store_t *const bs, const char *const filename) {
if (bs && filename) {
if (! FLAG_CHECK(bs, FILE_LINKED)) {
// Ok, I can make a giant complicated hunk of logic to:
// Create if it doesn't exist
// Increase size if smaller
// Decrease size if larger
// and It'll be a giant headache for various reasons (error checking, portability)
// OR, I can just do it in two commands and call it a day.
bs->fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP);
if (bs->fd != -1) {
if (utility_write_file(bs->fd, bs->data_blocks, BLOCK_COUNT * BLOCK_SIZE) == BLOCK_COUNT * BLOCK_SIZE) {
// Kill the DBM and dirty flag, set link state
bitmap_format(bs->dbm, 0x00);
FLAG_CLEAR(bs, DIRTY);
FLAG_SET(bs, FILE_LINKED);
bs_errno = BS_OK;
return;
}
bs_errno = BS_FILE_IO;
return;
}
bs_errno = BS_FILE_ACCESS;
return;
}
bs_errno = BS_LINK_EXISTS;
return;
}
bs_errno = BS_PARAM;
}
size_t block_store_export(const block_store_t *const bs, const char *const filename) {
// Thankfully, this is less of a mess than import...
// we're going to ignore dbm, we'll treat export like it's making a new copy of the drive
if (filename && bs && bs->fbm && bs->data_blocks) {
const int fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP);
if (fd != -1) {
if (utility_write_file(fd, bitmap_export(bs->fbm), FBM_SIZE * BLOCK_SIZE) == (FBM_SIZE * BLOCK_SIZE)) {
if (utility_write_file(fd, bs->data_blocks, BLOCK_SIZE * (BLOCK_COUNT - FBM_SIZE)) == (BLOCK_SIZE * (BLOCK_COUNT - FBM_SIZE))) {
block_store_errno = BS_OK;
close(fd);
return BLOCK_SIZE * BLOCK_COUNT;
}
}
block_store_errno = BS_FILE_IO;
close(fd);
return 0;
}
block_store_errno = BS_FILE_ACCESS;
return 0;
}
block_store_errno = BS_PARAM;
return 0;
}
// Block sync function to feed to bitmap_for_each
// Jumps the fd to the needed location and writes to it
// Admittedly, this function is not pretty.
void block_sync(size_t block_id, void *bs_sync_ptr) {
bs_sync_obj *bs_sync = (bs_sync_obj *)bs_sync_ptr;
/*
typedef struct {
int disaster_errno;
block_store_t *const bs;
size_t byte_counter;
bs_status status;
} bs_sync_obj;
*/
if (bs_errno == BS_OK) {
if (bs_sync && bs_sync->status == BS_OK) {
if (bs_sync->bs) {
if (FLAG_CHECK(bs_sync->bs, FILE_LINKED)) {
// Ducks = in a row
// jump to file position
if (lseek(bs_sync->bs->fd, BLOCK_POSITION(block_id), SEEK_SET) == BLOCK_POSITION(block_id)) {
// attempt to write
size_t written = utility_write_file(bs_sync->bs->fd, bs_sync->bs->data_blocks + BLOCK_POSITION(block_id), BLOCK_SIZE);
// Update written with WHATEVER happened
bs_sync->byte_counter += written;
if (written == BLOCK_SIZE) {
// all is ok, we wrote everything, or so we were told
return;
}
}
bs_sync->status = BS_FILE_IO;
// save whatever errno was generated by seek or write
bs_sync->disaster_errno = errno;
return;
}
bs_sync->status = BS_NO_LINK; // HOW DID THIS HAPPEN
return;
}
bs_sync->status = BS_PARAM;
}
bs_errno = BS_PARAM;
}
return;
}
